DrAmine
Ansys Employee

You understand my question: so if the motion has amplitude and frequency to be parameterized then you can provide these two as input paratmers in Fluent. On the UDF side you can access these two paramters to write your own DEFINE_CG_MOTION.

You do not need to use UDF for the distance: that is a parameter which you will set in SpaceClaim or DesignModeler.

Did you go though the standard Fluent tutorials?

How to access Input Parameters defined in Ansys Fluent in a user defined function: Check the Customization Manual of Ansys Fluent.